Compajt



6. L. WALKER.

BLOWPIPE.

APPLICATION FILED MAR. l9, l9l9| 1,310,099. Patented July 15, 1919.

IIIIIIIIII- V g z INVENTOR ATTORNEYS STATES PATENT omen.

GEORGE In. WALKER, OF NEW YORK, N. Y., ABBIGHOR To an. REDUCTION c mm 1110., a oonrona'rron or new roan.

' nnowrrrn. 1,310,099. hmmflbn Q Patent- Patented J uly 15 1919.

Application fled larch 10, 1919. Serial No. 888,588.

To all whom it may concern:

Be it known that I, Gnoncn L. WALKER, a citizen of the United States, residing at New York city, in the county of New York, State of New Yorkihave invented certain new and useful Im rovements in Blowpipes; and I do here y declarethe followmg to be a full, clear, and exact description ofthe invention, such as will enable others skilled in the art to, which it appertains to make and use the same.

invention relates to blowpipes em- 10 ing combustible mixtures to produce igh temperature flames for heating, weld:

ing and cutting operations andhas for its .obJect the accomplishment "of certain advantages in the operation of the blow ipe,

. among which is the prevention of ash back or ignition of the mixture within the blowpipe structure.

- Among other objects and advantages of Joy-invention is the provision of blowpipe structures particularly ada ted for. operation' in the manner hereina 1 described to accomplish the desired results.

These and other objects of my invention will be better understood by' reference to the following! specification when read' in con-" nection wm the accom anying drawing illustrating. the preferre mechanical embodiments of m invention in which:

Figure 1 is a ongitud-inal section through a blowpipe constructed in accordance with m l invention, and 85 another formof lowpipe embody? same principles of construction but i somewhat in mechanical details.

g. 2 is a lontudinal section through -%lowpipes of the character here inbefore -40 referred to are customarily supplied with an oxidizin and a combustible gaausuall oxygen an acetylene. ,Hereto ore it h s beenacfipted practiceftoadmit theoxyn e o ataf ressurecom 415 e i der a'bly hightrfiihn die acetylene. I havediscovered that advantageous results are possible wherethe' initial pressure of the acetylene is equal to or greater than that ofthe oxy n and particularly where the velocity of t2 acetylene at the int of mixture with the oxygen is *equa to or hi her than the-vclocit of the ox gen. 7

e primarydiflicu tywhih -propose to overcome through the practice of my .inventitn is the result of the phenomenon commonly called flashback in which the gaseous mixture becomes ignited and burns within the blowpi e structure. This phenomenon is depen ent u on the velocity 01 flame ropagation in t e mixture issuing 60 from t e tip and is influenced-by the deposit of carbon within. the dischar pa. Normally the velocity of the issuing mixture is maintained high enough to insure; against flame propagation backwardly into the dis- 66 charge passage. When, howeverythe discharge passage becomes partially obstructed as frequently occurs in ractice, the velocity of the issuing gases is owered and ignition of the mixture within the blowpipe struc- 0 'ture frequently occurs I have discovered that where the velocities'of the two gases at the point of mix-T ing are maintained equal, or the velocity 0f the acetylene is slightly higher than that ot the oxygen, the tendency'to flashback is substantially overcome and even when the discharge assage from the tip is partiallyobstru ,thevelocity of flame propagation rearwardlyin the discharge passage is lowered sufiiciently so that the decreased velocity of the issuing gases is sufficientto maintain the blowpipe in. operation.

ent of the mixture under conditions of decreased velocity at the outlet throu h the preponderance of the velocity of t e acetylene at the point 'of mixing. The

sameresult is, however noted where the velocities of the two see are substantially ,equal and Ibelieve at an e xplanationot the-result may be predicated upofi the fact that when the mixture-is uniform and in the 1 practised, any diminution of the velocity of the in the. discharge passage has results in an enrichment ofthd mixture in oxygen which ermitsof flame IO PIILgILtIOD' at a higher ve ocity. Hence t e increased velocity of flame Tropagation is balanced-abs a amst lower ve ocity of the gases and a hback occurs In carryin out n in-z vention, hewever a decreasedveocitythe gases in the di harge passage either does not cfiect'the mixture, or permits a slight Inlggneral I the result noted to the 85 enric proportions ior which the blowpipe is de- 95 j enrichment in acetylene. Th speed of flame propagation remains, the fore, constant or is slightly decreased and in any event is sufficiently low so that under usual I conditions no flashback occurs.

- When the ressure and velocit of the acetylene excee s the pressure an velocity of the oxygen, as introduced to the blowpipe, I have noted a characteristic condition which confirms my explanation of the reasons for \the peculiar henomenion ove described. The neutral ame which is produced when the blowpi is functiomn roperly resents a wel defined cone. I t e nose 0 the blowpipe-is brought into close relation with the work, so that the outlet is partially obstructed and then withdrawn, 'a momentary change is noted in the character of the cone, which becomes elongated and ragged. This condition is' characteristic of the presence of an excess of acetylene in the burning gases.

In carrying out'my invention it is preferable that the velocity of the acetylene exceed that of the :zygen, although it may be substantially eq thereto at the. point where the two gases are mixed within the torch. This may be accomplished by providing passages of equal cross sectional area through which the two gases are brought together andby regulating the supply of acetlens to substantially the same or a slightly igher pressure than that of the oxygen; The acetylene passage may, however, slightly smaller in cross sec ional area than. the oxygen passa and theacetylene pressure may berslig tly greater than that of the oxygen; There should be no enlargement of the outlet from the efcetylenepassage which would permit expansion of the gas and consequent drop in pressure efore it mixes with the oxy n. Preferably thetwo passages are broug together at a relatively sharp angle, the, cross sectional 7 area of the formed being lessthanths combinefistrbggsectiunal areas of the two ages may, however, e.

substantially parallel role; 'on' a liver the e F ambe'r. Variousotlier iment's, capableofutilization application of, my invention maybe devi and the inventionis in fact applicable to many otthe blow-pipes welljknown' and commonly: used I- have, however, illustrated in the accompany'ing drawing two forins of blowpipes which may be employed in carrymg out my invention the illustration to that. portlon of the may ipes m which the i mixing and dischargo the cferrin to Fig. 1 of'the drawing indicates; a eadhavinga contra 6. which is preferably runed before the d at s bent to shape respective g s s d l a sli ht y difierent delivered to thepass 1 ceding the same velqcit or indicatedin thed'rawing. A ti 7 having, a discharge 1;- is threadedlytor otherwise secured smaller cross sectional area t an t e passage 6 and is preferably countersunk atjzlgl at a relatively sharp an le so that rid abrupt shoulderoccurs at t e junction of'the two passages.

The oxidizing and combustible gases are delivered to the head through two pipes 12 and 13- prcferably concentrically arr'ang and adapted to deliver the see topassages 14 and 15 formed in a ler 16 which is threadedlyrsupported at the rear-end of, the head 5. he passage's l i and 15 are substantially of arallel and equal cross s ctional area and the gases are deliveredtherefrom to a frusto-conical chamber 17 communicating with'the passage 6. As previously pointed out the acetylenepassage 14 may be of slightly smaller cross sectional area than the oxygen passage 15 in which event, it would be necessalgeto maintain the acetylene at a slightly hi-g r presure' that of the oxygen. he two gases delivered to the chamber 17 issue from t eir respective passages at substantiall the. same velocity or the sect lone ma issue at a slightly higher velocity than't e oxygen. The gases are mixed in a chamber 17 and passage 6 and afie delivered to the discharge passage 8 of t 0 ti c In i 2 of the drawing, I have" illustrated whic 1-20 indicates a head a ti ,21 having a discharge passagerfigissecureg, any suitable manner, as. threads 23 on the" reduced end of the ti The hea with conver ng pass oxidizing; and combusti 1a,.

mus and.28 secured to the sad: em .ofthc .in passages 25 and'26';niayj.be. q l ll cross sectiizinal the. two gases may be delivered at thef ame pressure orthe acetylene pressure mayibe. s than' thepxygen pressuresfor acetylen may s; crglsshsection lharza than? w 'c event'a ig er. a I tainedon T118111 in a trusts-conical 9 the juncture of the assages ifliss e t thiac Em with; 'Weloci of c ylene slight y higher k tlianqthat of the I gardless of structure em r-tion 24: at the 8 if V 'head 5. The rear-end of the tip 7 is a conical surface 9coform of ny invention in for: example,

20 a. rovided'y 5.25 an 726 for snwhich are l the of. substanti ally slightly lows the application ,of the principle of maintainin the velocities of the two gases substantial y e ual t the point where they mix, or 'provi ing acetylene at a velocity higher than that of the ox gen at the polnt of mixture. Operation in t e manner described eflectually prevents flashback and permits continuous operation which is highly advantageous because it conserves the time of the operator as well as the heat lost in the work while the torch is frequently relighted. This and other advantages of my invention render it hi hly desirable in practice and it will be un erstood that in the embodiments hereinbefore described, I haveattempted merely to clearly explain the method of operation without intention to limit the invention to the specific mechanical structures illustrated.

Various changes may be made in the method of operation and in its application to blowpipes of varying construction without departing from the spirit and scope of the invention or sacrificing any of its material advantages.

: gases to commingle and thereby pro I claim: i

1. In the operation of blowpipes employed in heating, welding and cutting and burning mixtures of combustible and oxidizing gases, the methodwhich comprises, causln the ucing the combustible mixture and maintaining the ratio of velocities of the incoming gases so that the velocitycf the combustible gas is not substantially lower than that of'the oxidizin gas. 4

2. In t e operation of blowpipes employed in heating, welding and cutting and burning mixtures of combustible and oxidizing gases, the method which comprises, causing the gases to commingle and thereby producing the combustible mixture and maintaining the ratio of the velocities of the incoming gases so that the velocity of the combustible as is at least substantially equal to that of t e oxidizing gas.

3. In the operation of blowpipes, employed in heating, welding and cutting and urniug mixtures of combustible and oxidizing gases, the method which comprises, causing the gases to commingle and thereby producing the combustible mixture and maintaimng the ratio of the velocities of the incoming gases so that the velocity of the combustible gas is greater than that of the oxidizing gas.

4. In the operation of blowpipes employed in heating, welding and cutting and burning mixtures of combustible and oxidizing gases, the method which comprises, causing the gases to commingle and thereby producing the combustible mixture and maintaining the ratio of the velocities of the combustible and oxidizing gases so that enrichmentof the mixture in oxidizing gas isprevented.

5. In the operation of blowpipes employed ing the combustible mixture and maintaining the ratio of the velocities of the combustible and oxidizing gases so that the velocity of flame propagation in the mixture is prevented from exceeding the velocity of the mixture. a

6. In the operation of blowpipes em loy'ed in heating, welding, cutting and H e operations, and burning mixtures of combustible and oxidizing gases, the method which comprises, introducing combustible gas to the blowpipe at a pressure exceedin the pressure at which the oxidizing gas is introduced,.causin the gases to commingle, and discharging t elmixture.

In testimony whereof I aifix my signature.

GEORGE L. WALKER.

the gases to commingle and t ereby produc- 

